---
id: CVE-2025-38528
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Reject %p% format string in bprintf-like helpers

  static const char fmt[] = "%p%";
      bpf_trace_printk(fmt, sizeof(fmt));

  The above BPF program isn't rejected an…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Reject %p% format string in bprintf-like helpers

  static const char fmt[] = "%p%";
      bpf_trace_printk(fmt, sizeof(fmt));

  The above BPF program isn't rejected an…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.13, < 5.15.190'
  - 'linux_kernel >= 5.16, < 6.1.147'
  - 'linux_kernel >= 6.2, < 6.6.100'
  - 'linux_kernel >= 6.7, < 6.12.40'
  - 'linux_kernel >= 6.13, < 6.15.8'
  - linux_kernel = 6.16
  - debian_linux = 11.0
patched:
  - linux_kernel 6.15.8
published: '2025-08-16'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:18:44.843'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-38528'
references:
  - url: 'https://git.kernel.org/stable/c/1c5f5fd47bbda17cb885fe6f03730702cd53d3f8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/61d5fa45ed13e42af14c7e959baba9908b8ee6d4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6952aeace93f8c9ea01849efecac24dd3152c9c9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/97303e541e12f1fea97834ec64b98991e8775f39'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e7be679124bae8cf4fa6e40d7e1661baddfb3289'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f8242745871f81a3ac37f9f51853d12854fd0b58'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
epss: 0.00172
epssPercentile: 0.06531
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-15T21:51:29.402427Z'
ingestedAt: '2026-10-15T22:48:25.513Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

bpf: Reject %p% format string in bprintf-like helpers

static const char fmt[] = "%p%";
    bpf_trace_printk(fmt, sizeof(fmt));

The above BPF program isn't rejected and causes a kernel warning at
runtime:

    Please remove unsupported %\x00 in format string
    WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0

This happens because bpf_bprintf_prepare skips over the second %,
detected as punctuation, while processing %p. This patch fixes it by
not skipping over punctuation. %\x00 is then processed in the next
iteration and rejected.

## Affected

- `linux_kernel >= 5.13, < 5.15.190`
- `linux_kernel >= 5.16, < 6.1.147`
- `linux_kernel >= 6.2, < 6.6.100`
- `linux_kernel >= 6.7, < 6.12.40`
- `linux_kernel >= 6.13, < 6.15.8`
- `linux_kernel = 6.16`
- `debian_linux = 11.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.15.8`